Conventional methods for cooling an electric machine include passing a coolant around an outer perimeter of the electric machine inside of a cooling jacket. The coolant extracts heat from a stator of the electric machine. In some machine designs, the level of heat removal is increased by spraying coolant from the cooling jacket directly onto end turns of the stator. Gravity can drain the sprayed coolant toward the bottom of the electric machine's housing and a drain hole is often located near the bottom of the housing to exhaust the coolant. Typically, the drain is located at the geometric bottom center of the housing.
When properly sized for gravity-fed drainage, however, the typical drain location does not allow the spent coolant to substantially pool at the bottom of the housing. As a result, lower regions of the stator end turns can overheat. In addition, if the electric machine is tipped, excessive amounts of the coolant can pool within the housing around the electric machine. The pooled coolant can flood an air gap between the electric machine stator and the electric machine rotor, causing adverse effects such as relatively large spin losses and/or thermal failure of the electric machine.